JP2009010865A - Antenna system for light-transmissive rfid, and furniture and system using same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an antenna system for RFID capable of recognizing tag IDs in a plurality areas on the same plane. <P>SOLUTION: The antenna system for RFID comprises a glass substrate 20 which has light transmissivity and is formed in a plate shape, and a plurality of antenna patterns P which are provided on at least one surface of the glass substrate 20 and each made of a looped conductive thin film having light transmissivity. The plurality of antenna patterns P are provided adjacently such that each antenna pattern P surrounds almost all of respective areas 20a to 20d obtained by dividing the plane of the glass substrate 20 by the number of the antenna patterns P. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a light transmissive RFID antenna device for receiving information recorded in an RFID tag (hereinafter referred to as “tag ID” as appropriate) and furniture and a system using the antenna device. In addition, the present invention relates to a light transmissive RFID antenna device capable of receiving information on the relative positional relationship between the antenna device and the RFID tag, and furniture and a system using the same.

  In recent years, RFID tags (also called electronic tags, IC tags, etc.) have been used in RFID (Radio Frequency IDentification) technology, which is a non-contact information transmission means. As is well known, an RFID tag is a kind of information recording medium, and generally comprises an antenna for receiving / transmitting radio waves, a non-volatile memory (such as an EEPROM) for storing a tag ID, and a peripheral transmission / reception circuit. And an IC chip. When an RFID tag is brought close to a reader antenna connected to a reader for reading information, a transmission / reception circuit of the RFID tag receives radio waves from the reader antenna to generate operating power and is stored in a memory. The tag ID is read and transmitted toward the reader antenna. The tag ID data received by the reader antenna is transferred to and input to the reader, and various information processing based on the tag ID data is performed.

  Information processing application technology using such RFID tags has been rapidly developed in the merchandise distribution field, the medical field, and the like due to the fact that the external dimensions of the RFID tag have been significantly reduced and the manufacturing cost has been greatly reduced. The introduction is expanding. For example, Patent Document 1 is an application example in the field of merchandise distribution, and discloses an article shelf provided with a shelf board with an antenna for a reader. As shown in FIG. 1, the user can see the products displayed on the shelf boards 6 to 8 such as glass plates provided with the reader antenna 11 without being obstructed by the antenna. As described above, the antenna 11 is composed of an antenna pattern thin film having a certain transmittance or more, and information data is exchanged with the antenna 11 by placing a product to which the RFID tag is attached on the shelf boards 6 to 8. It is said that it has the effect that the product can be seen well without being disturbed by the antenna.

Further, in Patent Document 2, in an antenna device including a light transmissive antenna installed on a light transmissive base material or a light reflective base material, the light transmissive property or light reflective performance of the base material is not impaired. In order to supply an antenna device with excellent communication performance, it is a light transmissive antenna composed of at least one plane-filled figure partitioned by a linear partition region, and the light transmittance of the light transmissive antenna is 60 % Or more, the line width of the linear partition region is 0.1 to 100 μm, the light-transmitting antenna is installed on the base material, and the base material is a light-transmitting base material or a light-reflecting material. An antenna device is disclosed that is a base material.
JP2007-37899 JP 2006-186742 A

  However, although a transparent shelf board with a reader antenna can be obtained depending on the configuration of Patent Document 1 or Patent Document 2, information that can be read by the reader antenna is an RFID tag attached to a product or the like to be placed. Since only a unique tag ID (identifier) is obtained and only a binary value indicating whether or not the ID is present can be obtained, it was impossible to identify at which location on the same table or shelf it was read.

  Further, according to the configurations of Patent Document 1 and Patent Document 2, for example, when a reader antenna is provided on a shelf board, not only the tag ID attached to the article placed on the shelf board is read, but also below the shelf board. There is a risk that the tag ID of an article brought close to the item will be erroneously read.

The present invention has been made to solve the above and other problems.
One embodiment of the present invention provides:
A glass substrate that is light-transmissive and formed in a plate shape;
Provided on at least one surface of the glass substrate, each comprising a plurality of antenna patterns made of a loop-like conductive thin film having optical transparency,
The plurality of antenna patterns are provided adjacent to each other so that each pattern surrounds almost the entire area obtained by dividing the plane of the glass substrate by the number of antenna patterns.
This is an RFID antenna device capable of detecting a plurality of areas.
At this time, a plurality of regions obtained by dividing the number of the antenna patterns may be configured such that there are different areas in their areas.

In addition, at least a single loop-like conductive film pattern may be formed so as to be adjacent to each antenna pattern.
The plurality of antenna patterns are provided on one surface of the glass substrate, and a conductive thin film is formed on almost the entire surface of the other surface of the glass substrate to prevent unnecessary radio waves from entering the antenna pattern. A radio wave shield layer can be formed.

According to another aspect of the present invention, there is provided a glass plate material in which a glass top plate or a glass shelf including the RFID antenna device according to the aspect of the present invention is supported substantially horizontally by one or more support legs. The furniture using the glass plate material is characterized in that the antenna pattern of the RFID antenna device is provided on the upper surface of the glass substrate.
At this time, it is preferable that the lead wire drawing position from each antenna pattern to the RFID reader / writer is set at a position closest to any one of the support legs.

Another aspect of the present invention provides:
A glass substrate that is light-transmissive and formed in a plate shape;
An antenna pattern comprising a light-transmitting loop-shaped conductive thin film provided on each surface of each glass substrate;
Between the antenna patterns facing each other in the thickness direction of the glass substrate, a radio wave shield layer provided over almost the entire surface of the glass substrate,
An antenna device for RFID, comprising:

The radio wave shielding layer can be formed of the same conductive thin film as the antenna pattern.
The glass substrate has a laminated glass structure in which a conductive thin film is sandwiched between two sheet glass materials, and the radio wave shielding layer can be constituted by the conductive thin film.

  According to the RFID antenna device according to the aspect of the present invention, the antenna pattern on the glass substrate is not conspicuous, so that the application is widened, and depending on where the article with the RFID tag attached is placed on the glass substrate. Since the antenna for reading the information of the RFID tag can be made different, various information processing can be performed based on the information including the position information on the glass substrate in addition to the tag ID stored in the RFID tag. If the area of each antenna pattern is set so that there are different areas, the information reading sensitivity can be changed depending on the antenna pattern. Furthermore, if at least a single loop-like conductive film pattern is formed so as to be adjacent to each other along the antenna pattern, the reception sensitivity of the antenna pattern can be increased. Further, if a radio wave shielding layer made of a conductive thin film is provided on the side opposite to the antenna pattern installation surface, it is possible to prevent reception of noise incident on the antenna pattern from an unintended direction.

  Further, in the furniture using the glass plate material according to another aspect of the present invention, different information processing may be performed depending on where the article attached with the RFID tag is placed on the same glass top plate or shelf. it can. If the lead wire drawing position from each antenna pattern is set to the position closest to one of the support legs, the lead wire is not noticeable and the design effect is enhanced.

  Furthermore, according to another aspect of the present invention, the antenna patterns provided on both surfaces of the glass substrate are separated by the radio wave shielding layer interposed between the two patterns, so that the tag ID incident from the side of each antenna pattern It is possible to receive the radio wave carrying the signal independently on each side and perform information processing based on it.

  Hereinafter, the present invention will be described with reference to the accompanying drawings in accordance with the embodiment.

《RFID antenna device》
FIG. 1A is a plan view of an RFID antenna device according to an embodiment of the present invention, and FIG. 1B is a partial cross-sectional view thereof. This RFID antenna device (hereinafter abbreviated as “antenna device”) 10 is configured for a use frequency of 13.56 MHz, and has four antenna patterns formed on a 330 mm square glass substrate 20. . That is, the glass substrate 20 is divided into four equal regions 20a to 20d when viewed in plan, as shown by broken lines in the figure, and the antenna pattern P is formed along the boundaries of the respective regions 20a to 20d. ing.

  In forming the antenna pattern P, first, a conductive film (not shown) is formed on almost the entire surface of one side of the glass substrate 20. Then, blasting or chemical treatment is performed in a masked state so as to obtain a desired pattern shape, and the remaining portion is removed while leaving the conductive film in the shape of the antenna pattern P. This conductive film is disclosed in, for example, Japanese Patent Laid-Open No. 2006-169088, and is preferably a metal oxide such as ITO or tin oxide, and has a film thickness of 1 μm or less to provide light transmission. If an intermediate film (not shown) having a thickness of about 0.3 to 2 mm is adhered to the glass substrate 20 on which the antenna pattern conductive film is formed, the unevenness on the glass substrate 20 generated at the time of blasting. Is filled with an intermediate film and becomes almost transparent.

  The antenna pattern P formed in the antenna device according to the present embodiment includes three loop patterns P1 to P3. The outermost pattern P1 is a transmission / reception antenna that exchanges tag ID data with an RFID tag. A feeder portion F is formed at a portion corresponding to each vertex of the rectangular glass substrate 20, and lead wires L are provided at both ends of the pattern P1. Connected. The lead wire L drawn out is drawn into the RFID reader device, which will be described later.

  In the antenna device 10 of the present embodiment, for each antenna pattern P, two closed loop patterns P2 and P3 are formed on the inner side of the pattern P1 constituting the transmission / reception antenna so as to be substantially along this. These patterns P2 and P3 exhibit a function of improving reception sensitivity by inducing induced current by radio waves from the RFID tag and combining the induced magnetic field with the transmission / reception antenna pattern P1. The sensitivity improving loop pattern may be provided so as to be adjacent to the transmission / reception loop pattern P1 on a plane as in the present embodiment, or may have a certain length in the pattern thickness direction via the glass substrate 20. Even if they are provided so as to be separated and adjacent to each other, that is, stacked in the thickness direction of the glass substrate 20, the same sensitivity improving function is exhibited.

  FIG. 2 shows a loop pattern P2 for improving sensitivity in the thickness direction so that one transmission / reception antenna pattern P1 (FIG. 2A) provided on the glass substrate 20 is laminated on the transmission / reception antenna pattern P1. The structure which provided (FIG.2 (b)) adjacent is shown. The illustration corresponds to one circuit of the antenna pattern in FIG. 1A. The glass substrate 20 on which the antenna pattern P1 and the loop pattern P2 are respectively formed is bonded in a sandwich shape with the laminated intermediate film M interposed therebetween to obtain the antenna device of FIG. At this time, it is preferable that the outer periphery of the loop pattern P2 has a shape and dimension that substantially matches the inner periphery of the antenna pattern P1.

  In the present embodiment, the conductive film pattern width of the transmission / reception loop pattern P1 is set to 10 mm so as to be suitable for transmitting and receiving radio waves of 13.56 MHz, but this may be determined as appropriate depending on the intended characteristics. Similarly, the sensitivity improving loop patterns P2 and P3 may be appropriately determined so as to obtain desired characteristics. Further, as shown in the figure, each loop pattern P1 to P3 has an R attached to the pattern bent portion, but this is for improving the radio wave characteristics of the loop pattern, and the radius of R may be appropriately determined. . However, as the distance from the transmitting / receiving antenna pattern increases, that is, as it goes inward, it is better to make the width of the sensitivity improving loop pattern narrower than the outside. The same can be said when the above-described antenna pattern for transmission / reception is laminated with the loop pattern for improving sensitivity.

  As shown in the cross-sectional view of FIG. 1B, noise waves are prevented from entering the antenna pattern P through the glass substrate 20 on the surface of the glass substrate 20 opposite to where the antenna pattern P is provided. It may be preferable to provide a radio wave shield layer S for this purpose. When the radio wave shield layer S is provided, the radio wave shield layer S is formed on almost the entire surface on the opposite side of the antenna pattern P so as to block radio wave incidence on the antenna pattern P from the surface side. The radio wave shield layer S can be formed by depositing a conductive thin film similar to the antenna pattern P on the surface of the glass substrate 20. The radio wave shield layer S may be grounded as necessary.

<< RFID antenna device shape and pattern >>
Next, the shape and pattern of the antenna device will be described. 3A and 3B are diagrams schematically showing the planar shape of the antenna device and the type of the antenna loop pattern.

  First, as the planar shape of the antenna device, for example, a circle or a triangle may be considered in addition to the square (square) of the above-described embodiment. Needless to say, this shape is not limited to these, and can be appropriately determined based on the use of the antenna device, the installation location, the external design requirements, and the like. In addition, the number and shape of the areas where the antenna patterns are arranged may be determined corresponding to the planar shape of the antenna device. FIG. 3A and FIG. 3B show a state in which antenna patterns are arranged in each region by dividing into two to eight regions as an example. For example, when three regions are set for a circular antenna device, a loop pattern is formed along the outer periphery of each sector region obtained by dividing the circular center into three equal parts. Note that the schematic diagrams of FIGS. 3A and 3B include those in which the area of the area is not necessarily equal, such as an example in which the area of the rectangular glass substrate is divided into five or six. In this case, the antenna pattern set in a region having a relatively smaller area than the other based on the directivity of each antenna pattern has a narrower RFID tag reading range, in other words, information is transferred compared to other regions. Since a difficult place exists on the glass substrate 20, it is possible to perform weighting relating to operability such as being easy to read and difficult to read according to the type of information processing based on the reception result. In other words, the area associated with the important information operation can be configured such that it cannot be read unless the RFID tag is consciously brought close thereto by reducing the area relatively. That is, the place to read and the place not to read can be selected intentionally.

  3A and 3B also show variations of the relationship between the shape of the antenna device, the number of pattern regions, and the number and arrangement of supports (support legs) for supporting the entire antenna device. This mainly relates to, for example, the configuration of a table provided with the antenna device of the present embodiment on a glass top plate. In each schematic diagram, a black circle (•) attached to each pattern represents the position of the feed portion which is a lead wire drawing portion from each pattern. With respect to the configuration in which the circular device is provided with three regions, each pattern feeder is provided as shown in the case where one column is provided at the center of the circle and when columns are provided at a 120 ° pitch on the circular circumference. Although the position of the part F is varied, in this case, the position of the feeder part is set to the closest position of the nearest support column. This is because the entire antenna device is almost transparent, so that the lead wire taken out from the feeder portion F cannot be concealed. Therefore, the lead wire L taken out from the feeder portion F is immediately drawn into the column so as not to stand out. Or, it is appropriate to wire along the support.

  In order to show this more clearly, FIG. 4A and FIG. 4B show an antenna device 10 that includes a circular glass substrate 20 and that has regions 20a to 20c obtained by dividing the glass substrate 20 into three equal parts. 4A shows an example in which a column 30 is provided at the center of the circular glass substrate 20, and FIG. 4B shows an example in which three columns 30 are provided at a 120 ° pitch on the circumference of the circular glass substrate 20. As apparent from these drawings, the feeder portions F of the loop patterns P and P1 to P3 are arranged so as to terminate in the cross-sectional profile of the support column 30, respectively. The presence of the lead wire L is not visible from the outside and does not impair the beauty.

<< Operation of RFID antenna device >>
Next, the operation of the four-loop pattern antenna device including the square glass substrate according to the embodiment will be described as an example. Since the rectangular glass substrate 20 is provided with the antenna pattern P in each of the four regions divided into four equal parts, when an article with an RFID tag attached is brought close to or placed on each antenna pattern P, Each antenna pattern P can receive tag ID data stored in an RFID tag. On the other hand, by discriminating each antenna pattern P by the reader device that receives the reception data from the antenna device 10, the antenna device 10 uses the position information on the glass substrate 20 in addition to the tag ID data stored in the RFID tag. Four types of data can be sent in correspondence. Further, since the loop pattern is set so as to cover the entire area of each area, the information data of the RFID tag can be read at any position on the entire glass substrate 20.

《Application example (table furniture)》
Next, table furniture using the antenna device 10 of the embodiment will be described. 4A is a plan view of the table furniture and glass table 100, and FIG. 4B is an elevation view thereof. An antenna device 110 including a rectangular glass substrate 120 having four antenna patterns P similar to that in the above embodiment is supported by four hollow cylindrical pillars 130 at four corners. A glass top plate 140 constituting the top plate of the glass table 100 is placed on the upper surface of the antenna device 110. The antenna pattern P is formed on the upper surface of the glass substrate 120, and an intermediate film (not shown) is bonded and protected except for the feeder portion F to which the lead wire L is connected.

  A control unit box 150 is arranged below the antenna device 110 with a space therebetween, and the control unit box 150 is fixed at a position where the four corners of the control unit box 150 are slightly lifted from the lower end of the column 130 by the column 130. The control unit box 150 accommodates a RFID tag information data reader device and peripheral devices (not shown) such as a power supply unit. The reader device has a support column from each feeder unit F of four antenna patterns P. A lead wire L drawn into the control unit box 150 via 130 is connected. Various general-purpose reader devices for 13.56 MHz can be used as the reader device. Here, there are four antenna inputs, and a reader device (for example, manufactured by Takaya Corporation) that can identify inputs from four antennas. "TR3-LD003D-4" type reader / writer) is used.

  The output from the reader device is input to a personal computer (PC) or the like via an interface circuit, and predetermined information processing is performed. Peripheral circuit devices such as a PC and a power supply unit can be housed in the control unit box 150 together with a reader device as necessary. As an example of control application, consider the operation of a DVD player, for example. Assume that four antenna patterns P are identified as antenna [1] to antenna [4] as shown in FIG. 4A. An RFID tag storing at least “information indicating that the media contained in the case is a DVD” and “unique information identifying the content recorded on the DVD” is attached to the DVD storage case. And When the DVD case is placed on the top plate 140 of the glass table 100, the information indicating that the placed article is a DVD and the contents of the DVD is read by any of the antennas [1] to [4]. It is done. Since the reader device identifies which antenna [1] to [4] was read at the same time, for example, antenna [1] → main menu, antenna [2] → main part playback, antenna [3] → skip, antenna By associating with the DVD player operation system such as [4] → back, different operations can be easily performed depending on the place where the DVD case is placed. Similarly, by identifying an other medium such as a CD and assigning an operation corresponding to another device operation system for each antenna, various operations can be performed depending on the place where the media case is placed.

  It can also be created as a showcase for clothes and applied to product displays and explanations, such as changing clothes, skirts, trousers, etc. on the antenna pattern and putting them on the screen.

<< Modification of RFID antenna device >>
Next, a modification of the RFID antenna device according to the present invention will be described. FIG. 6A is an exploded perspective view of this modification, and FIG. 6B is a partial cross-sectional view of this modification. As will be described later, this modification makes it possible to incorporate an RFID as a facility unlocking and entering / leaving management system. For example, if it is required to hold a card when leaving a room, the usage status of the room and the current number of users can be grasped on the system.

  The RFID antenna device 10 ′ includes two glass substrates 20, and a conductive film similar to that formed in the RFID antenna device according to the above-described embodiment is formed on one surface of each glass substrate 20. A loop antenna pattern P is formed. A radio wave shield layer S made of a conductive thin film similar to the antenna pattern P is formed almost entirely on the surface of any one of the glass substrates 20 (upper glass substrate in this modification) where the antenna pattern P is not formed. Form it. Then, the surface of the radio wave shield layer S of one glass substrate 20 and the surface of the other glass substrate 20 on which the antenna pattern P is not formed are opposed to each other and are intimately contacted with each other through the intermediate film M. It should be noted that the configuration of the present invention in which the two antenna patterns P are separated by the radio wave shield layer S, regardless of the combination of the glass substrate on which the antenna pattern P is formed and the glass substrate on which the radio wave shield layer S is formed. There is no problem as long as it is obtained. In addition to the conductive thin film, the radio wave shielding layer S can be made of a metal sheet material such as a metal mesh or punching metal used for meshed glass. The radio wave shield layer S may be grounded as necessary.

  In the example shown in the figure, one antenna pattern P is provided on each surface. Of course, two or more antenna patterns P may be provided on each surface. For example, as in the embodiment of the present invention described above, each surface may be divided into a plurality of areas, and a plurality of antenna patterns P may be installed so as to cover each area. Furthermore, in this case, the number of divisions of the regions on each surface is not necessarily the same, and the number of antenna patterns P may be different on each surface. Further, similarly to the above-described embodiment, it is also possible to provide a loop pattern for improving sensitivity.

  According to the RFID antenna device 10 ′ having such a configuration, the conductive radio wave shield layer S is interposed between the antenna patterns P facing each other with the glass substrate 20 interposed therebetween. The received tag ID is not erroneously received by the other (opposite) antenna pattern P. In other words, in the example illustrated in FIG. 6A and FIG. 6B, tag ID data can be recognized separately when received by the antenna pattern P on one side and when received by the other antenna pattern P. Thus, the amount of information transmitted by the tag ID can be increased.

<< Application of RFID Antenna Device Modification >>
By using the RFID antenna device according to the above-described modification, for example, an entrance / exit management system for managing entry / exit of a person into / from a certain indoor space can be configured. FIG. 7A is a front view of a glass door used in the system, and FIGS. 7B and 7C are partial sectional views of an RFID antenna device that can be suitably used for the glass door of FIG. 7A.

  In this example, a glass door 70 is attached to a wall 78 in the building. For convenience of explanation, it is assumed that the front side of the paper is an outdoor room and the back side of the paper is a room separated by a glass door 70. In the glass door 70, a door glass 72 having light permeability is assembled to the door sash 74, and the door sash 74 is attached to the outer frame 79 fitted on the wall surface of the building by a hinge 76. It constitutes a pivotable door. An RFID antenna device 10 ′ is provided on a part of the door glass 72. The antenna device 10 ′ includes antenna patterns P1 and P2 formed on both opposing surfaces of the door glass 72, and a radio wave shield layer S that electromagnetically isolates the patterns P1 and P2. Has been. Although not shown, an auto-lock device that unlocks and locks the glass door 70 in accordance with the reading of the tag ID can be provided.

  Next, the configuration of the RFID antenna device 10 'will be described in more detail. FIG. 7B is a partial cross-sectional view showing an embodiment of the antenna device 10 ′. The door glass 72 includes two plate glasses 20, and antenna patterns P1 and P2 are formed on one side of each plate glass 20 where the antenna device 10 'is to be provided. A radio wave shield layer S made of a conductive thin film is formed on the surface of any one of the glass plates 20 where the antenna patterns P1 and P2 are not formed, and the antenna patterns P1 and P2 are electromagnetically separated. The two glass plates 20 are bonded to each other on the surfaces where the antenna patterns P <b> 1 and P <b> 2 are not formed and sandwich the intermediate film M to form the door glass 72. In this embodiment, since the antenna patterns P1 and P2 are formed on both surface sides of the door glass 72, a resin film or the like having light transmittance is applied to the door glass 72 so that at least the antenna patterns P1 and P2 are protected. It is desirable to affix to each side of the. Further, as the laminated intermediate film M, for example, a film having a thickness of 0.1 mm to 1.5 mm made of polyvinyl butyral (PVB) or ethylene vinyl acetate (EVA) can be used.

  FIG. 7C is a partial cross-sectional view showing another embodiment of the antenna device 10 ′. The door glass 72 includes three glass substrates 20. Antenna patterns P1 and P2 are formed on one side of each of the two glass substrates 20. A conductive thin film is formed on one surface of the third glass substrate 20 to form a radio wave shield layer S. The two glass substrates 20 on which the antenna patterns P1 and P2 are formed are sandwiched by sandwiching the third glass substrate 20 on which the radio wave shield layer S is formed so that the antenna pattern side is on the inner side. Adjacent glass substrates 20 are bonded together with an intermediate film M interposed therebetween. In the case of the door glass 72, the antenna patterns P1 and P2 are disposed inside the door glass 72, and therefore, unlike the previous embodiment, a special protective material such as a resin film is not necessary. The area inside the antenna loop patterns P1 and P2 is printed by printing, sandblasting, or appropriate characters, numbers, patterns, pictograms, etc., such as a room number, an appropriate logo, or a display indicating the tag ID reading position. It can be used to arrange by such a method.

  In any of the embodiments, the lead wires L drawn from the antenna patterns P1 and P2 are routed through the door sash 74 and taken out from an appropriate position to the building-side wall 78, and an appropriate tag ID reader device (not shown). ). The tag ID reader device delivers the read tag ID data to an entrance / exit management system (not shown) together with an ID indicating which antenna pattern is received.

  Next, the operation and effect of the entrance / exit management system will be briefly described. When a person who wants to enter the room from the outside of the room in FIG. 7A approaches the antenna device 10 ′ of the glass door 70 with his / her identification card attached with a predetermined RFID tag, the reading is performed. The tag ID data thus transferred is transferred to a system server (not shown) via the reader device. The system server inquires whether the received tag ID data belongs to a regular registered employee, and if it is regular data, the glass door 70 is unlocked and the owner of the tag ID enters the room. In the system log. If it is not confirmed that the data is legitimate, unlocking is not performed. For example, a message for alerting a voice device (not shown) is output, and processing such as recording in the system log that an abnormal access has occurred is performed. Execute. Conversely, the same processing is performed when going out of the room. As a system, it is possible to distinguish entry / exit by determining whether the signal is received by the outdoor antenna or the indoor antenna, and can be recorded together with the tag ID in the system log. Therefore, if such a glass door 70 is provided at the entrance of each room in the building, it is possible to apply in real time who knows who is in which room.

1 is a plan view of an RFID antenna device according to an embodiment of the present invention. It is a fragmentary sectional view of the antenna apparatus for RFID of FIG. 1A. (A)-(c) is a schematic diagram which shows the example which laminated | stacked the antenna pattern for a sensitivity improvement with respect to the antenna pattern for transmission / reception in the antenna apparatus for RFID which concerns on one Embodiment of this invention. It is the schematic diagram 1 which shows the type of the planar shape of the RFID antenna device which concerns on one Embodiment of this invention, antenna pattern arrangement | positioning, and the support | pillar arrangement | positioning for supporting. FIG. 3 is a second schematic diagram showing a type of a planar shape, an antenna pattern arrangement, and a support arrangement for supporting an RFID antenna device according to an embodiment of the present invention. 1 is a plan view of an RFID antenna device according to an embodiment of the present invention, which is an example in which a circular glass substrate 20 is divided into three, an antenna pattern is disposed, and a support column 30 is provided at the center thereof. 1 is a plan view of an RFID antenna device according to an embodiment of the present invention, in which an antenna pattern is arranged by dividing a circular glass substrate 20 into three, and three pillars are arranged at a 120 ° pitch on the circumference of the circular glass substrate 20. 30 is an example. It is a top view of the glass table which is one Embodiment of this invention. FIG. 4B is an elevation view of FIG. 4B. It is a disassembled perspective view which shows the modification of the antenna apparatus for RFID which concerns on this invention. It is a fragmentary sectional view which shows the modification of the antenna apparatus for RFID which concerns on this invention. It is a figure of the glass door for entrance / exit management systems comprised using the modification of the antenna apparatus for RFID which concerns on this invention. It is sectional drawing of the RFID antenna apparatus 1 used suitably for the glass door of FIG. 7A. It is sectional drawing of the RFID antenna apparatus 2 used suitably for the glass door of FIG. 7A.

Explanation of symbols

10, 10 'RFID antenna device 20 Glass substrate 20a, 20b, 20c, 20d Region (partitioned on glass substrate 20)
30, 130 Prop (support leg)
70 Glass door 100 Glass table 140 Glass top plate 150 Control box P, P1, P2, P3 Antenna loop pattern F Feeder part S Radio wave shield layer M Matching interlayer L Lead wire

Claims (9)

A glass substrate that is light-transmissive and formed in a plate shape;
Provided on at least one surface of the glass substrate, each comprising a plurality of antenna patterns made of a loop-like conductive thin film having optical transparency,
The plurality of antenna patterns are provided adjacent to each other so that each pattern surrounds almost the entire area obtained by dividing the plane of the glass substrate by the number of antenna patterns.
An RFID antenna device characterized by the above.   2. The RFID antenna device according to claim 1, wherein among the plurality of regions obtained by dividing by the number of antenna patterns, there are ones that are different from each other in area.   2. The RFID antenna device according to claim 1, wherein at least a single loop-shaped conductive film pattern is formed so as to be adjacent to each other along the antenna patterns.   The plurality of antenna patterns are provided on one surface of the glass substrate, and a conductive thin film is formed on almost the entire surface on the other surface side of the glass substrate to prevent unnecessary radio waves from being transmitted to the antenna pattern. The RFID antenna device according to claim 1, comprising a radio wave shielding layer for preventing incidence. A glass top plate or a glass shelf provided with the RFID antenna device according to claim 1 is a furniture using a glass plate material, which is supported substantially horizontally by one or more support legs,
Table furniture, wherein an antenna pattern of the RFID antenna device is provided on an upper surface of a glass substrate.   6. The furniture using a glass plate material according to claim 5, wherein a lead wire drawing position from each antenna pattern is set at a position closest to any one of the support legs. A glass substrate that is light-transmissive and formed in a plate shape;
An antenna pattern comprising a light-transmitting loop-shaped conductive thin film provided on each surface of each glass substrate;
Between the antenna patterns facing each other in the thickness direction of the glass substrate, a radio wave shielding layer provided over almost the entire surface of the glass substrate,
An RFID antenna device comprising:   The RFID antenna device according to claim 7, wherein the radio wave shielding layer is formed of the same conductive thin film as the antenna pattern.   The RFID substrate according to claim 7, wherein the glass substrate has a laminated glass structure in which a conductive thin film is sandwiched between two sheet glass materials, and the conductive thin film constitutes the radio wave shielding layer. Antenna device.

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